Maharashtra Board Class 6 Science Solution Chapter 5 – Substances in the Surroundings –Their States and Properties
Balbharati Maharashtra Board Class 6 Science Solution Chapter 5: Substances in the Surroundings –Their States and Properties. Marathi or English Medium Students of Class 6 get here Substances in the Surroundings –Their States and Properties full Exercise Solution.
|Maharashtra Class 6|
Substances in the Surroundings –Their States and Properties
1.) In the paragraph below, write ‘ solid’, ‘liquid’or’ gas ‘ in each of the brackets depending on the substance referred to just before.
On a bright sunny day , Riya and Gargi are playing with a ball (solid) in the park . Gargi feels thirsty, so Riya brings tender coconut water (liquid) for her.At the same time, a strong breeze (gas) starts blowing and it also begins to rain( liquid).They run back into the house (solid), change their clothes (solid ) and then their mother give them a cup( solid) of hot milk( liquid) to drink.
2.) Discuss .
a.) Riya pours some water from her bottle into another bottle. Does it change the shape of the water?
Yes, it will change the shape of the water . The shape of the water will change because liquid has a constant volume but it does not have a definite shape . So, liquid will adapt to the shape of its container in which it is poured.
b .) Halima picks up a small stone from the ground and puts it in the water in a dish.Does the shape of the stone change?
No, the shape of the stone will not change because solid has a fixed shape and volume . The particles present in solid does not flow freely, so it is difficult to change the shape of solids. Solids always try to sustain its own shape, without getting acclimated to the shape of its container.
3.) Write the properties of these substances.
- Water – The properties of water are its fluidity and transparency.
- glass – The properties of glass are its transparency and brittleness.
- chalk – The properties of chalk are its brittleness..
- iron ball – The properties of iron ball are its hardness.
- sugar – The properties of sugar are its solubility.
- salt – The properties of salt are its solubility.
- flour – The properties of flour are it’s solubility.
- coal – The properties of coal are its brittleness.
- soil – The properties of soil are it’s solubility.
- pen – The properties of pen are it’s hardness.
- ink – The properties of ink are it’s fluidity.
- soap – The properties of soap are it’s brittleness.
4.) What is sublimation? Write the names of everyday substances that sublimate.
Sublimation refers to a process in which, the solid state directly get’s transformed into gaseous state without getting transformed into liquid state.Camphor and naphthalene balls are two such examples, that undergoes the process of sublimation.
5.) What it is made from ? Why ?
a.) A sickle to cut sugarcane.
A sickle that is used to cut sugarcane is composed of iron. As sickle is made of iron, so it is extremely strong and hard. Iron also depicts other features such as ductility and malleability. As sickle is used for cutting sugarcane, so a strong tool is required ,for that reason sickle is composed of iron.
b.) The sheets used for roofing.
The sheets that are used for roofing is made up of aluminium. Aluminium shows characters such as malleability. Malleability portrays the ability of a metal to be contorted to such an extent that it goes beyond compression. So, it can be hammered into thin sheets.
c.) A screwdriver.
A screwdriver is composed of tough steel. Screwdriver portrays characters like hardness and durability. As screwdriver is primarily used for inserting and removing the screws, for that reason screwdriver is made up of steel.
d.) A pair of tongs.
A pair of tongs is mostly composed of iron or aluminium. The thermal conductivity of these metals are extremely high, so they are unlikely to melt ,when they are used on flames.
e.) Electric cables .
Electric cables are composed of copper, aluminium. In order to make wires, these metals are used. Copper is mainly used for making wires because copper is considered as a good conductor of electricity and has low level of resistivity.
Ornaments is mainly made up of gold or silver. Because of it’s prominent luster and great quality, gold is considered as the most preferred metal for manufacturing jewellery.
g.) Pots and pans .
Pots and pans are made up of copper because it depicts a good thermal conductivity.
6.) What will happen if ——— ? And why ?
a.) Nails are made of plastic.
Nails are mainly used for the purpose of moulding. So, if nails are composed of plastics, then it will fail to resist the pressure that is applied at the time of hammering.
b.) A bell is made of wood .
A bell is primarily used for the purpose of ringing. So, if a bell is made up of wood, then it will fail to serve its purpose. A bell is usually composed of copper, so it depicts other characters like sonority , which means a ringing sound will be produced when strucked with any object. Wood does not possess this character, so it is not possible to make a bell out of wood.
c.) Rubber is not fitted on a pair of tongs.
A pair of tongs is mostly composed of metal and metal shows the property of high thermal conductivity. So, if rubber is not fitted on the tongs , then it might burn the hands of the users because they are highly conductive to heat.
d.) A knife is made of wood.
A knife is generally used for the purpose of cutting fruits and vegetables. The knife that we use on a daily basis, are mainly composed of iron. The prominent characteristics of iron are its hardness, ductility, malleability and durability. So, if knife is composed of wood, then it could not be used for the usual purposes.
e.) An axe is made of rubber.
An axe is mostly used for the purpose of cutting wood. An axe is usually composed of metals, that displays eminent properties like hardness and durability. As rubber does not depicts these characteristics, so it could not be used for cutting hard things or objects.
7.) Who am I ?
a.) I ‘m found in a thermometer , I measure your temperature – Mercury
b.) I make things hot or cold – Temperature
c.) I have no shape whatsoever ! – Gas
d.) I dissolve in water, but not in kerosene – Salt
8) Why does this happen ?
a.) Coconut oil thickens in winter.
Coconut oil is composed of both saturated and unsaturated fats. The saturated fat contained in coconut oil is about 90% and unsaturated fat is only 10% . When the temperature is extremely high, then it remains in its liquid form but it converts into a solid state when the temperature decreases in winter. Coconut oil thickens in winter because it contains a high percentage of saturated fats. But oils like sunflower oil or mustard oil does not turn into solid even in winter because they are not attributed to the higher percentage of saturated fats.
b.) Kerosene left open in a dish disappears.
Kerosene left uncovered in a container disappears because the volatility of kerosene is quite high. So, it evaporates slowly when it is left open.
c.) The fragrance of incense sticks lighted in one corner of a room spreads to the other corner.
The fragrance of incense sticks lighted in one corner of a room spreads to another corner because a smoke is released from the sticks when it is lighted ,along with a aroma. For that reason, smoke spreads rapidly from one corner of a room to another corner which contains the fragrance. Therefore, making the whole room filled with a pleasant smell.
d.) What you see in the picture.
Two things are mainly depicted in the picture. The first thing is a balloon that is floating above the water surface and the second thing is an apple that is immersing at the bottom of the water. The balloon has lower density as compared to water, for that reason it is floating on the water surface ,on the other hand, the density of an apple is more in comparison to water, for that reason the apple is sinking to the bottom of the water.